1 files changed, 24 insertions, 5 deletions

diff --git a/lib/libc/regex/regcomp.c b/lib/libc/regex/regcomp.c
index a01bb95..2f2d827 100644
--- a/lib/libc/regex/regcomp.c
+++ b/lib/libc/regex/regcomp.c
@@ -192,6 +192,7 @@ regcomp(regex_t * __restrict preg,
 	struct parse *p = &pa;
 	int i;
 	size_t len;
+	size_t maxlen;
 #ifdef REDEBUG
 #	define	GOODFLAGS(f)	(f)
 #else
@@ -213,7 +214,23 @@ regcomp(regex_t * __restrict preg,
 	g = (struct re_guts *)malloc(sizeof(struct re_guts));
 	if (g == NULL)
 		return(REG_ESPACE);
+	/*
+	 * Limit the pattern space to avoid a 32-bit overflow on buffer
+	 * extension.  Also avoid any signed overflow in case of conversion
+	 * so make the real limit based on a 31-bit overflow.
+	 *
+	 * Likely not applicable on 64-bit systems but handle the case
+	 * generically (who are we to stop people from using ~715MB+
+	 * patterns?).
+	 */
+	maxlen = ((size_t)-1 >> 1) / sizeof(sop) * 2 / 3;
+	if (len >= maxlen) {
+		free((char *)g);
+		return(REG_ESPACE);
+	}
 	p->ssize = len/(size_t)2*(size_t)3 + (size_t)1;	/* ugh */
+	assert(p->ssize >= len);
+
 	p->strip = (sop *)malloc(p->ssize * sizeof(sop));
 	p->slen = 0;
 	if (p->strip == NULL) {
@@ -1405,8 +1422,8 @@ static void
 findmust(struct parse *p, struct re_guts *g)
 {
 	sop *scan;
-	sop *start;
-	sop *newstart;
+	sop *start = NULL;
+	sop *newstart = NULL;
 	sopno newlen;
 	sop s;
 	char *cp;
@@ -1709,15 +1726,17 @@ computematchjumps(struct parse *p, struct re_guts *g)
 	if (p->error != 0)
 		return;
 
-	pmatches = (int*) malloc(g->mlen * sizeof(unsigned int));
+	pmatches = (int*) malloc(g->mlen * sizeof(int));
 	if (pmatches == NULL) {
 		g->matchjump = NULL;
 		return;
 	}
 
-	g->matchjump = (int*) malloc(g->mlen * sizeof(unsigned int));
-	if (g->matchjump == NULL)	/* Not a fatal error */
+	g->matchjump = (int*) malloc(g->mlen * sizeof(int));
+	if (g->matchjump == NULL) {	/* Not a fatal error */
+		free(pmatches);
 		return;
+	}
 
 	/* Set maximum possible jump for each character in the pattern */
 	for (mindex = 0; mindex < g->mlen; mindex++)